You braze copper with a copper brazing rod. It does require a certain amount of skill and practice.
you solder or braze it
it is not easy to weld hard materials....it always difficult to hard materials.....
carefully
yes
I am interested in the answer to the posed question, can you cad weld re bar to copper ground wire? If you can do you protect the dissimilar metals with No-ox or some other treatment? No treatment of the copper cable to rebar in necessary after the exothermic weld is complete (Cadweld). Just pour concrete.
JB Weld
Yes, the compression fittings designed for copper work on both soft and hard copper pipes.
tig or mig depending on the wall thicknessCopper to copper is either soft soldered, or silver solderedSilver solder is a bad term as "solder" normally means lead content according to the AWS
Because copper is very hard and does not get damaged.
To effectively weld copper pipe for plumbing projects, you should clean the pipe and fittings thoroughly, apply flux to the joint, heat the joint evenly with a torch, and then solder the joint with a soldering iron. Make sure to practice proper safety precautions and follow manufacturer's instructions for the soldering materials.
No, copper pipes need to either be soldered, or connected with compression fittings. PVC cement will not bond with copper and provide a "solvent weld", it would be a very weak connection.
No, hard copper pipe will split when you try to flare it.